Pyrazinone conjugates as potential cephalosporin allergens

Cephalosporins with an α-amino group on the 7-β-acyl substituent have been shown to undergo aminolysis with subsequent formation of a fluorescent pyrazinone degradation product. An analogous reaction seems to take place upon in vitro conjugation of such cephalosporins to albumins and polylysine. A corresponding pyrazinone–polylysine conjugate was able to bind IgE antibodies in sera from patients with suspected allergy to β-lactams. These findings may have applications in the diagnosis of allergy against aminocephalosporins.